AI Controlled NPCs on the Tabletop
Most tabletop games are played either players versus each other or cooperatively the players against the world (mostly board games). We wanted to change that.
In a pen & paper game any NPC (Non-Player Characters) would require either complex rules, simplified logic or a 3rd player, a gamemaster, to control them. In Lands of Ruin none of that is required. The companion app, Lands of Ruin Command Console, takes the role of gamemaster and controls the AI (Artificial Intelligence) NPCs.
In this article we explain how AI works in Lands of Ruin and talk about our future plans to take it to the next level.
The Third Side - Backstory
The battlefield is not empty. Players' tribes confront remnants of the final war in the form of automated drones, decaying battle mechs still executing their wartime orders, and hordes of infected dead, all controlled by the companion app's AI.
The AI NPCs in the world of Lands of Ruin consist mostly of remnants of the weapons developed during the apocalyptic war that ended civilization. However, some wasteland tribes and surviving megacities still produce some of these weapons.
During the decades of the final war, fresh human soldiers became less available to join the conflict, so the wealthier nations of the conflict developed a new generation of autonomous war machines to continue the war effort. These drones were sent into the growing wasteland battlefields to fight against enemy armies, as well as the drones of other nations.
As the war dragged on, however, most nations had no remaining scholars or wealth to create such advanced machines, so the ranks of these nations' armies were bolstered with advanced bio-weapons: man-made diseases and hybridized mutant soldiers. All of these terrors were released into the wastes of the world to fight each other in unending combat… but the barriers of the war zones failed to contain these murderous hordes and clouds of pestilence for long.
The war eventually ended, once the flame of humanity was nearly snuffed out, but the machines and bio-weapons did not disappear, nor did they surrender when their operators perished. The autonomous drones and mechs kept executing their last commands; holding their ground, patrolling, and seeking the enemy. Mutants and designer plagues continued to multiply, spread, and thrive in the wastelands.
These leftover dangers litter the wastelands like an abandoned, mobile minefield, and tribes of the outland must face them on a daily basis.
During any game of Lands of Ruin, players will find that they are not only battling their opponent, but that each of them is also contending with the environment of the world through the use of these AI controlled NPCs.
In the first version of LoR we have implemented AI controlled Rotters (zombies) but we have a lot planned in the future.
But Why NPCs on Tabletop?
NPCs on the tabletop add a whole new dimension to wargaming. The games are no longer simply between two players and their characters. NPCs create more variation from game to game without making games more random.
Our Design Principles
When we started to design our AI NPCs we had few key design principles that were important to us:
- AI must be predictable.
- No added randomness.
- Must not slow down the game.
- The game must be fully playable withhout a gamemaster.
With these principles in mind we spent more than two years creating the current mechanisms of Lands of Ruin that allowed us to create a game in which players always have 3rd party on the table.
Rotters in Lands or Ruin
Let's take a look how Rotters work in Lands or Ruin. As we explained in a previous blog post, the Command Console companion app tracks and performs a lot of things automaticalyl without the players' intervention. One of these automatically things is noise tracking.
Every weapon, or more accurately firing mode, has a noise value. Whenever a character performs an attack this noise is added to the map section the attack is performed.
At the start of the Environment phase the Command Console app calculates noise values of each section and the section with most cumulative noise draws the Rotters on table towards it.
The cumulative noise dissipates slowly and a loud weapon will keep drawing the Rotters towards the place it was fired for few more turns unless similarly loud noise is generated elsewhere.
Once the target section is decided the app then compares noise made by characters currently in the section. The character who made the most noise this turn will be selected the target for this turn. If there are no characters in the target section the Rotters move towards the center of the section.
This simple logic makes the Rotters predictable. A player knows that if they open up with a machine gun while no other fighting is going on on the table it will flag them and that map section as the Rotter target for turns to come.
You can read detailed rules for Rotters in our Rulebook. Download a free PDF from our downloads page.
Another level of gameplay
The logic and predictability creates another level of gameplay that is rarely present in tabletop games.
Firing your weapon might not be the best option every time. You might keep it quiet and force your enemy to fire first and pull all the Rotters on the table.
In other situations it is possible to use the Rotters against your enemy. If there is an enemy between you and the Rotters, for example, causing a lot of noise will pull the Rotters towards you but as they reach your enemy characters before they reach you they become your enemy's problem.
Throwable weapons like grenades or specialised noise making machines can be used to direct the Rotters. Throwing a loud grenade into a building and then retreating will pull the Rotters towards that building.
These advanced tactics become highly interesting once players learn how the AI reacts.
For the initial release we create 3 Rotter types: normal Shamblers, fast moving Ragers, and armoured veterans:
You can read more about Rotters, their background and the types of Rotters from our Voices from the Waste ebook. Download it free from the Downloads page.
The Rotters is just the first step and a proof of concept for us. We're already working on the next iteration of the AI system.
The Command Console app tracks much more than just noise. It also allows us to run complex algorithms without making it difficult or complex to the players.
We already have two NPC types under construction but we've been talking and planning many more.
Mutants are attracted to blood as well as noise of battle. With these monsters the app will take into account multiple factors like where characters were hit and how badly they were wounded. Bleeding characters will continue attracting the mutants until bleeding stops.
All of the calculations and algorithms can be done automatically by the software.
Drones and Battlemechs
Drones and Mechs are remnants of the final war. They still execute their commands long after their command structure has collapsed.
The drones and mechs are executing predefined programs and guided based on them. These programs differ from drone to drone.
Drone programs can be predicted by players by observing their behaviour or in some cases by hacking into the drone's control software.